WHY Do I look the way I LOOK?

Everything you see in the mirror-from your height to your hair color to the dimple (or lack thereof) on your chin-is written into nearly every cell of your DNA, spiraling chains of proteins found in every cell in your body.
Think of DNA as your body’s instruction manual. It tells your cells how to grow into organs, hair, teeth, fingernails, your tongue, and every single other part of your body. Stretches of DNA (called genes) are like pages in that instruction manual. Genes control what you will look like, plus less obvious traits such as whether you have perfect vision or the ability to curl your tongue.